WINDSCREEN WIPER BLADE CLIP AND BACKING STRIP

Abstract: A wiper blade clip (50) for securing a backing strip (10) of a windscreen wiper blade assembly. The backing strip (10) comprises first and second pairs of rails (20, 22), either of which can be engaged with claws (12) of the blade frame depending on the size of the claws (12), and two channels (34, 36) for alternately receiving a wiper element (40), depending on which of the pairs of rails (20, 22) are engaged with the claws (12). The clip (50) comprises first and second pairs of legs (54, 56), which overlie the first and second pairs of rails (20, 22) and are spaced apart different distances corresponding to the rails (20, 22). The legs (54, 56) have prongs (58) which, depending on the pairs of rails (20, 22) is engaged by the claws (12), engage behind the claws (12) to limit longitudinal movement of the backing strip (10) relative to the claws (12). The clip (50) can be formed in two separate halves, each half having a respective one of the firt and second pairs of legs (54, 56).

Description: WINDSCREEN WIPER BLADE CLIP AND BACKING STRIP This invention relates to a windscreen wiper blade clip and to a backing strip. Windscreen wiper blade assemblies generally comprise a blade frame which carry articulated levers having opposed claws for slidably receiving a backing strip which supports a rubber blade element. Motor vehicle manufacturers generally manufacture wiper blade assemblies with claws having various widths for receiving backing strips of a predetermined size. In view of the fact that the wiper blade assemblies include claws of different widths, manufacturers of replacement backing strip and blade elements have developed a single backing strip which is able to fit different size claws of the blade assembly. Conventional backing strips comprise a first pair of rails which have longitudinal edges spaced apart a first predetermined distance (for example, corresponding to a 6 mm claw) and a second pair of rails having longitudinal edges which are spaced apart a second predetermined distance greater than the first predetermined distance (for example, corresponding to a claw of 8 mm) . Adjacent the rails which are spaced apart the second predetermined distance, a recess is provided for receiving the blade element so that the blade element extends outwardly to engage and wipe a windscreen of a vehicle. If the backing strip is to be used with a blade assembly having 6 mm claws, the 6 mm claws are engaged with the first pair of rails to secure the backing strip in the blade assembly. If the backing strip is to be used with a blade assembly having 8 mm claws the second pair of rails are engaged with the claws to secure the backing strip in the blade assembly. However, in order to engage the second pair of rails with the claw it is necessary for the bulk of the backing strip including the first pair of claws to be accommodated within the claws. In some instances the space available within the claws is not sufficient to accommodate the bulk of the backing strip and therefore if the backing strip is to be engaged with an 8 mm claw insufficient room is provided within the claw to accommodate the backing strip and the backing strip cannot be engaged with the second pair of rails. In order to secure the backing strip in place a clip is secured at the end of the backing strip. The clip has a pair of legs which are provided with prongs which engage behind the claws to secure the backing clip to the claws to prevent the backing strip from sliding out of the claws. However, because the backing strip is intended to be used with claws which are of different width, it is possible that the legs and prongs will not securely engage with the claws and that the clip can disengage from the claws thereby enabling the backing strip to slide relative to the claws and become disengaged or at least partially disengaged from the blade frame. The object of a first aspect of the present invention is to provide a clipping arrangement which provides a more secure engagement of the backing strip with the claws. The present invention may be said to reside in a windscreen wiper blade assembly clip for a windscreen wiper blade assembly having a blade frame including plural pairs of opposed claws, a backing strip having first and second channels for alternatively receiving a wipe blade element, the backing strip having a first pair of rails which include longitudinal edges spaced apart by a first predetermined distance and a second pair of rails having longitudinal edges spaced apart by a second predetermined distance which is greater than the first predetermined distance, the backing strip being coupleable to the blade frame by engaging either the first or second pair of rails with the opposed claws depending on the size of the opposed claws, and by the blade element being located in the first or second channels dependent upon which of the first or second pair of rails are engaged with the opposed claws, said windscreen wiper blade assembly clip including: a base section for location at an end of the backing strip; a first pair of legs coupled to and extending transverse to the base section and adapted to overlie the first pair of rails of the backing strip, the first pair of legs being spaced apart by a first predetermined distance; a second pair of legs coupled to and extending transverse to the base second and being opposed to the first pair of legs, the second pair of legs being adapted to overlie the second pair of rails, the second pair of legs being spaced apart a second predetermined distance which is greater than the first predetermined distance at which the first pair of legs are spaced; abutment members on each of the first and second pair of legs; attachment means for attaching the clip to the backing strip; and wherein dependent on which of the first or second rails are engaged with the opposed claws, the first or second pair of legs which overlie that pair of rails are, in use, engaged with one pair of the opposed claws by location of the abutment members behind said one pair of opposed claws to secure the backing strip to the one pair of opposed claws to limit longitudinal movement of the backing strip relative to the opposed claws. Since the backing strip can be orientated so that a desired one of the first or second pair of rails engages the claws dependent on the size of the claws, an appropriate pair of legs on the clip can also engage the claws to ensure that the legs match the size of the claws and therefore securely and snugly hold the backing strip to the claws. The fact that the wiper blade element is engageable in either first or second channels in the backing strip with which the clip is to be used also means that the first or second rails can be engaged with the claws without the need to accommodate the other of the first or second rails within the confines of the claws and therefore if the backing strip includes only first and second pair of rails there is no problem with accommodating the bulk of the backing strip within the claw and the backing rail can therefore be used with a wide variety of different claw configurations. Preferably each abutment member is defined by a prong located at an end of each leg in the first and second pair of legs. Preferably the attachment means comprises a securing tab located between the first pair of legs or the second pair of legs, the securing tab, in use, being folded and puncturing the backing strip to secure the clip to the backing strip. Preferably the prongs have tapered side edges for camming engagement with the one pair of opposed claws so that the prongs can easily engage behind the one pair of opposed claws. Preferably the legs have cutout sections between the prongs and the base section and fingers arranged transverse to the legs, the fingers being, in use, arranged beside the first and second pair of rails so that the prongs limit movement of the backing strip in one longitudinal direction and the cutout section and fingers limit movement of the backing strip in the opposite longitudinal direction. Preferably the backing strip comprises a centre web, a first pair of arms extending perpendicular to the centre web in a first direction and a second pair of arms extending perpendicular to the centre web in a second direction opposite the first direction, the first pair of rails being arranged at ends of the first pair of arms and extending perpendicular to the first pair of arms and parallel to the centre web, the second pair of rails being arranged at ends of the second pair of arms and being perpendicular to the second pair of arms and parallel to the centre web. Preferably the first and second channels are defined between the first pair of arms and the centre web and between the second pair of arms and the centre web respectively. Preferably the first and second pair of rails have inwardly directed flanges which define restricted entrance slots into the first and second channels. Preferably the blade element has a base portion, a neck portion and a wiper portion, the base portion and the neck portion being a slidable fit into one of the channels and one of the restricted entrance slots and the wiper portion extending outwardly from the backing strip. A second aspect of the invention may be said to reside in a backing strip for a windscreen wiper blade assembly, the windscreen wiper blade assembly having a blade frame including pairs of opposed claws, the backing strip including: first and second channels for alternatively receiving a wiper blade element, the backing strip having a first pair of rails which include longitudinal edges spaced apart by a first predetermined distance and a second pair of rails having longitudinal edges spaced apart by a second predetermined distance which is greater than the first predetermined distance, the backing strip being coupleable to the blade frame by engaging either the first or second pair of rails with the opposed claws dependent upon the size of the opposed claws, and by the blade element being located in the first or second channel dependent upon which of the first or second pair of rails are engaged with the opposed claws; a first clip arranged at one end of the backing strip and having a pair of legs which overlie the first pair of rails, the legs being spaced apart by a first predetermined distance; a second clip arranged at the other end of the backing strip and having a pair of legs which overlie the second pair of rails, the second pair of legs being spaced apart by a second predetermined distance which is greater than the first predetermined distance at which the first legs are spaced apart; abutment members on each of the first and second pair of legs of the first and second clips; and wherein dependent upon which of the first or second pair of rails are engaged with the opposed claws, the legs of the first or second clip which overlie that pair of rails are engageable with one of the opposed pair of claws so that the abutment members are arranged behind the said one of the pair of opposed claws to secure the backing strip to the one pair of opposed claws to limit longitudinal movement of the backing strip relative to the opposed claws. A third aspect of the invention may be said to reside in a backing strip for a windscreen wiper blade assembly which assembly includes plural pairs of opposed claws for engaging the backing strip and holding the backing strip in the blade assembly, said backing strip comprising: a first pair of rails having longitudinal side edges which are spaced apart by a first predetermined distance; a second pair of rails which have longitudinal edges spaced apart by a second predetermined distance; and a third pair of rails which have longitudinal side edges spaced apart by a third predetermined distance. By including three sets of rails the backing strip of this aspect of the invention is able to be used with wiper blade assemblies which have claws of three different spacings. The claws being arranged with an appropriate one of the rails having regard to the spacing of the claws to thereby enable the backing strip to be used with at least three different claw spacings. Preferably the backing strip includes a centre web: a first pair of arms extending transverse to the centre web in a first direction; the first pair of rails being arranged on the first pair of arms; a second pair of arms extending transverse to the centre web in a direction opposite to the first pair of arms; the second pair of rails being arranged on the second pair of arms; and the third pair of rails being defined by an extension of the centre web. Preferably the backing strip has a first channel for receiving a blade element which is defined between the first pair of arms and the centre web and a second channel for alternatively receiving the blade element depending upon which of the first or second pair of rails are engaged with the claw of the blade assembly, the second channel being defined between the second pair of arms and the centre web. Preferably the first and second pair of rails include inwardly directed flanges which define a restricted entrance slot to the first and second channels. Preferably the clip as previously described is used to secure the backing strip to one of the pair of opposed claws. A fourth aspect of the invention may be said to reside in a backing strip and clip combination for a windscreen wiper blade assembly which has opposed claws for receiving the backing strip, including: a backing strip having at least first and second pairs of rails for engaging the opposed claws of the windscreen wiper blade assembly; a clip arranged at one end of the backing strip and having; a) a base section for location at the end of the backing strip; b) a first pair of legs overlying the first pair of rails of the backing strip, a second pair of legs overlying the second pair of rails, and an attachment tongue for engaging the backing strip and securing the clip to the backing strip; and wherein the clip is held firmly to the backing strip by the base section which prevents substantial movement of the clip relative to the backing strip in a first direction parallel to the longitudinal direction of the backing strip, the attachment tongue which prevents substantial movement of the clip away from the backing strip in a direction opposite the first direction, the first pair of legs which prevent substantial movement of the clip in a third direction perpendicular to the longitudinal direction of the backing strip, and the second pair of legs which prevent substantial movement of the clip in a fourth direction perpendicular to the longitudinal axis of the backing strip and opposite to the third direction. The invention still further provides a backing strip and clip combination for a windscreen wiper blade assembly having a blade frame including plural pairs of opposed claws, the backing strip having first and second channels for alternatively receiving a wipe blade element, the backing strip having a first pair of rails which include longitudinal edges spaced apart by a first predetermined distance and a second pair of rails having longitudinal edges spaced apart by a second predetermined distance which is greater than the first predetermined distance, the backing strip being coupleable to the blade frame by engaging either the first or second pair of rails with the opposed claws depending on the size of the opposed claws, and by the blade element being located in the first or second channels dependent upon which of the first or second pair cf rails are engaged with the opposed claws, said windscreen wiper blade assembly clip including: a first pair of legs overlying the first pair of rails of the backing strip, the first pair of legs being spaced apart by a first predetermined distance; a second pair of legs opposed to the first pair of legs, the second pair of legs overlying the second pair of rails, the second pair of legs being spaced apart a second predetermined distance which is greater than the first predetermined distance at which the first pair of legs are spaced; abutment members on each of the first and second pair of legs; attachment means for attaching the clip to the backing strip; and wherein dependent on which of the first or second rails are engaged with the opposed claws, the first or second pair of legs which overlie that pair of rails are, in use, engaged with one pair of the opposed claws by location of the abutment members behind said one pair of opposed claws to secure the backing strip to the one pair of opposed claws to limit longitudinal movement of the backing strip relative to the opposed claws. Preferred embodiments of the invention will be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a perspective view of a backing strip according to the preferred embodiment of the invention; Figure 2 is a perspective view of a clip according to a first embodiment of the invention; Figure 3 is a top view of the clip of figure 2; Figure 4 is a side view of the clip of figure 2; Figure 5 is a view of a backing strip mounted to a claw of a windscreen wiper blade assembly; Figure 6 is a view similar to figure 5 showing the alternative mounting of the backing strip; Figure 7 is a view showing the clip of figure 2 mounted on the backing strip of figure 1; Figure 8 is a view showing a second embodiment of the invention; Figure 9 is a view showing a backing strip according to a second embodiment of the invention; Figures 10, 11 and 12 show the backing rail of figure 9 engaged with different claws of a windscreen wiper blade assembly; and Figure 13 shows a cross-sectional view of a wiper blade element according to an embodiment of the invention. With reference to figure 1, a backing strip 10 is shown which is to be engaged with claws 12 (see figures 5 and 6) of a vehicle windscreen wiper blade assembly. As is well known, windscreen wiper blade assemblies include a blade frame (not shown) which is coupleable to a pivot shaft (not shown) of a motor (not shown) for driving the blade assembly to wipe a vehicle windscreen (not shown) . The blade fame supports a plurality of the opposed claws 12 on articulated levers which are carried by the blade frame. This structure is well known and therefore will not be described in further detail. The opposed claws 12 are generally aligned with one another in a direction transverse to the longitudinal axis of the backing strip 10. However, it should be understood that the reference to opposed claws in this specification is also intended to cover arrangements where the claws 12 are staggered with respect to one another. The backing strip 12 according to the preferred embodiment of the invention has a centre web 14. A first pair of arms 16 extend perpendicular to the web 14 in a first direction and a second pair of arms 18 extend perpendicular to the web 14 in a second direction opposite to the first direction. The ends of the first pair of arms 16 support a first pair of rails 20 and the ends of the second pair of arms 18 support a second pair of rails 22. The first and second pair of rails 20 and 22 have longitudinal edges 24 and 26 respectively. The longitudinal edges 24 of the first pair of rails are spaced apart a first predetermined distance and the longitudinal edges 26 of the second pair of rails 22 are spaced apart a second predetermined distance which is greater than the first predetermined distance. The first and second pair of rails 20 and 22 have inwardly extending flanges 30 which, between respective pairs of the flanges 30, define restricted entrance slots 32. A first channel 34 and a second channel 36 are respectively defined by the centre web 14 and first pair of arms 16 and by the centre web 14 and second pair of arms 18. As is shown in figures 5 and 6, the channels 34 and 36 receive a wiper blade element 40 for wiping the windscreen so that the wiper blade element is securely connected to the backing strip 10. The channels 34 and 36 may have abrasions, barbs or the like (not shown) for releasably securing the wiper blade element 40 in one of the channels 34 or 36. The backing strip 10 shown in figure 1 is a multifit backing strip intended for use with claws which are spaced apart by different distances. Typically, some vehicle manufacturers produce wiper blade frames which have claws which are spaced apart a distance of, for example, 6 mm and others produce wiper blade frames which have claws which are spaced apart by a distance of, for example, 8 mm. Other manufacturers or vehicle models can have a claw spacing of 12.5 mm. The distance between the longitudinal edges 24 of the first pair of rails 20 is intended to match claws which are spaced apart a distance of, for example, 6 mm and the distance between the longitudinal edges 26 of the second pair of rails 22 is adapted to match claws which are spaced apart a larger distance, for example, 8 mm. When attaching the backing strip 10 shown in figure 1 as original equipment on the motor vehicle or removing an existing backing strip and attaching a replacement backing strip the appropriate pair of rails 20 or 26 which match the spacing of the claws 12 are engaged with the claws 12 as shown in figures 5 and 6 so that the rail is slid through the plurality of opposed pair of claws 12 to couple the backing strip 10 to the blade frame of the windscreen wiper blade assembly of the vehicle. The wiper blade element 40 shown in figures 5 and 6 is engaged with the channel 34 or 36 which is arranged outwardly of the claws 12. If necessary the blade element 40 can be moved from one of the channels and inserted in the other channels depending upon which of the rails 20 or 26 are engaged with the claws 12. As shown in figure 5, the rails 26 are engaged with the claws 12 and therefore the blade element 40 is engaged in the channel 34. As shown in figure 6 the rails 20 are engaged with the claws 12 and the blade element 40 is coupled with the channel 36. Figure 5 of the drawings shows claws 12 which are arranged as a clover leaf member whereas the claws 12 in figure 6 are rectangular or trapezoidal in cross- sectional shape. Since the backing strip 10 is engageable with the claws by simply reversing the position of the backing strip and locating the blade element 40 in an appropriate one of the channels 34 or 36 it is not necessary for the unused set of rails to be accommodated within the confines of the claw and therefore the backing strip would readily fit claws regardless of the configuration of the claws or the amount of space within their confines. As is also best shown in figures 5 and 6, the blade element 40 includes a base portion 42 which is received within the channel 36 or 34, a neck portion 44 which is received in the associated restricted entrance slot 30 and a wiper portion 46 which is adapted to wipe on a windscreen of a vehicle. An intermediate web portion 48 may be arranged between the wiper portion 46 and the neck 44 if desired. Preferably the rail 12 is formed by extrusion from plastics material and the wiper element 40 is also formed from extrusions 40 from a suitable soft flexible rubber or plastics material. Figures 2, 3, 4 and 7 show a clip 50 which is adapted to be arranged at one end of the backing strip 10 and which is adapted to secure the backing strip 10 to one pair of opposed claws 12 of the blade frame. The clip 50 has a base section 52 which is intended to be arranged adjacent the end of the backing strip 10. A first pair of legs 54 extend transversely, and preferably perpendicular, to the base 52 and are spaced apart by a first predetermined distance. A second pair of legs 56 are generally opposed to the first pair of legs 54 and also extend transverse and, preferably perpendicular, to the base section 52. The second pair of legs 56 are spaced apart a second predetermined distance which is greater than the first predetermined distance at which the legs 54 are spaced. Each of the legs 54 and 56 is provided with a prong 58 at its end. The prongs 58 have tapered outer side walls 60 for camming engagement with the claws 12 as will be described hereinafter. The legs 54 and 56 also have cutouts 62 arranged between the prongs 58 and the base 52. A securing tab 64 is arranged between the pair of legs 56 and is adapted to be folded and forced to puncture the centre web 14 of the rail 10 in order to secure the clip to the rail 10. A suitable tool (not shown) can be used to fold the securing tab 64 into the position shown in figure 2 so that portion 64a is driven through centre web 14. The legs 56 and 54 both have fingers 66 which extend towards one another and transverse to the legs 56 and 54. As is best shown in figure 7, the clip 50 is arranged on the rail 10 by locating base section 52 adjacent the end of the rail and with the legs 56 overlying the second pair of rails 22 and the first pair of legs 54 overlying the first pair of rails 20, the tab 64 is bent as previously described so that it passes between the flanges 30 and penetrates the centre web 14. As is shown in figures 5 and 6, when the backing strip is slidably engaged with the claws 12, one of the opposed pair of claws 12 will abut the tapered side wall 60 of the prongs 58 and by camming engagement the legs will flex inwardly so that a continued sliding movement will locate the prongs 58 behind the claws 12 to secure the clip and therefore the backing strip 10 to the claws 12 and therefore the wiper frame of the wiper blade assembly. Since the legs 56 and 54 are spaced apart by different distances which correspond with the distance between the longitudinal edges 24 and 26 of the first and second pair of rails 20 and 22 and which in turn match the spacing of claws used with vehicle blade assemblies, the appropriate pair of legs 56 and 54 are spaced to match the claws with which they engage so that the prongs 58 securely engage behind the claws and securely fasten the backing strip to the claws. The fingers 66 extend downwardly beside the pairs of rails 20 and 22. Thus, the prongs 58 will limit longitudinal movement of the backing strip 10 in the direction of arrow A in figure 7 when the prongs 58 are engaged behind the claws 12. Movement in the opposite direction shown by arrow B in figure 7 is prevented by virtue of the fingers 66 and the appropriate cutouts 62 engaging the claws 12. Thus, when the claws 12 are located behind the prongs 58 the backing strip 12 is securely located relative to the claws 12 and therefore the blade frame of the wiper blade assembly. In order to release the backing strip 12 from the blade frame for replacement or maintenance etc, it is only necessary to flex the legs 54 or 56 towards each other so that the prongs 58 are disengaged from behind the claws 12 and the backing strip 10 can then be slid relative to the claws 12 to disengage the backing strip from the claws 12. The legs 54 or 56 which are not engaged with the claws 12 are protected from the windscreen (not shown) of a vehicle by the wiper blade element 40 and therefore cannot contact the windscreen and scratch the windscreen. In the preferred embodiment of the invention shown in figures 2, 3, 4 and 7, the legs 54 and 56 are integral with the base section 52 and form a single clip. However, in other embodiments, the clip could be formed in two clip halves, each clip half having a respective pair of legs 54 and pair of legs 56. The clip halves would have base sections arranged at the end of the rail but the base sections would not be joined together so the clip halves are effectively separate from one another. Figure 8 shows a second embodiment of the invention in which the rail 10 is identical to that pre iously described. However, in this embodiment two separate clips 70 and 80 are provided at opposite ends of the backing strip 10. One of the clips 70 is engaged with the rails 20 and the other clip is engaged with the rails 22. The clips 20 have a single pair of legs 72 which are of the same structure as the legs described with reference to the clip 50 shown in figures 2 to 7. The legs 72 are spaced apart a first predetermined distance corresponding to the rails 20 and therefore the claws which will engage those rails and legs 82 of the clip 80 are spaced apart a second predetermined difference corresponding to the rails 22 and therefore the claws which will engage that rail. The legs 72 and 82 have prongs 74 and 84 and function in exactly the same manner as the legs of the clip 50. The clips 70 and 80 also have cutouts 78 and 88 and fingers 90 and 92 which function in the same manner as the corresponding fingers and cutouts in the clip 50. Figures 9 to 12 show a second embodiment of a backing strip 100. The backing strip 100 is generally the same as the backing strip 10 and similar reference numerals denote similar parts. However, in this embodiment the centre web 14 is extended outwardly to provide a third pair of rails 102 which have longitudinal edges 104. The longitudinal edges 104 are spaced apart a third predetermined distance corresponding to a third spacing of claws used in vehicle windscreen wiper blade assemblies of, for example, 9.40 mm. The clip 50 which is generally identical to the clip previously described, is used with the rail 100. Figures 10 and 11 are similar to figures 5 and 6 and show the opposed claws 12 engaged with the rails 20 and 22 and with the appropriate prongs 58 of the clip 50 securing the backing strip 100 to the claws 12. Once again, the wiper blade element 40 is engaged with an appropriate one of the channels 34 or 36 depending upon which of the rails 20 or 22 are engaged with the claws 12. Figure 12 shows the third pair of rails 102 engaged with the claws 12. When the third set of rails 102 are engaged with the claws 12 it is preferred that the smaller rails 20 be accommodated within the confines of the claws 12 and that the prongs 38 associated with the first pair of legs 54 engage behind the claws 12 to secure the backing strip 100 in place. However, depending on the configuration of the claws 12 and the amount of space within the confines of the claws 12, the rails 22 could be located within the confines of the claws 12 and the blade element 40 located in the recess 34 instead of in the recess 36. Once again the prongs 38 prevent movement of the backing strip relative to the claws 12 in one direction and the fingers 66 and cutouts 62 prevent movement of the backing strip 100 relative to claws 12 in the opposite direction. Thus, the embodiment of figures 9 to 12 provides three pairs of rails of different spacing for use with three different claw sizes so that the one backing strip can be used with blade frames having three difference claw sizes. The clip 50 may be secured to the backing strip 10 or 100 by a securing tab which pierces the centre web 14 as previously described or by any other convenient method. For example, a serrated tab or barb could be provided which engages arms 16 or 18 to secure the clip in place, a hole could be punched in the backing strip and a tongue could engage that hole to secure the clip to the backing strip, or a tongue could be provided which includes a hole for receiving a rivet to secure the clip to the backing strip etc. The clip 50 is securely held to the backing strip 10 and cannot accidentally detached from the backing strip 10 or move to any substantial extent relative to the backing strip 10. When the clip 50 is attached to the backing strip 10, the base section 52 prevents the clip 50 from moving in a first direction shown by arrow B parallel to the longitudinal axis of the backing strip 10. The tongue 64 which engages the backing strip 10 and preferably pierces the web 14 prevents the clip from moving in a second direction A opposite the first direction. The legs 56 prevent the clip 50 from moving in a generally vertical direction shown by arrow C and the legs 54 prevent the clip 50 from moving upwardly in the direction of arrow D. Thus, the clip is securely retained at the end of the backing strip 10. Figure 13 shows a preferred embodiment of the wiper blade element 40 used with the preferred embodiment of the invention. As previously described, the wiper blade element 40 has a base 42, a neck 44, an intermediate wiper portion 48 and a wiper portion 46. The intermediate wiper portion 48 is of substantial thickness and provides a shock absorber or snubber section which absorbs loads applied from the wiper section 46 and reduces the load applied to the wiper blade assembly. Intermediate wiper portion 48 is also provided with a pair of stops 49 which limit the amount of pivotal movement of the wiper portion 46 in the direction of double headed arrow E about hinge portion 45 which extends between the intermediate wiper portion 48 and the wiper portion 46. The stops 49 which limit the amount of pivotal movement of the wiper portion 46 help in the prevention of "set" which is a tendency of the wiper portion to remain pivoted in one direction and not to flip in the opposite direction as the wiper blade commences its return stroke on a windscreen. If the wiper portion 46 remains set, it tends to chisel water from the windscreen rather than wiping the water from the screen which results in increased noise and low cleaning performance. The stops 49 also ensure that the wiping lip 47 is presented at the most desired wiping angle with respect to the windscreen. The wiper portion 46 is also provided with a pair of score lines or grooves 57 which operate as a further hinge to ensure the tip 47 makes the proper lip angle to the windscreen in either direction. The score lines or grooves 57 also aid in flipping of the wiper portion 46 as the return stroke commences. The surface of the wiper blade element 40 may be case hardened in a standard chlorination process. The case hardening of the surface of the wiper blade element 40 increases resistance to gouging, cutting and tearing during use and deterioration when the element encounters dust, sand, salt, insects, grime or other harsh substances. Wiper element 40 is normally extruded in the form of two wiper elements 40 being mirror images of one another. The extrusion is cut in half at foot 59 to provide discrete wiper elements 40. The case hardening takes place before cutting of the extrusion so that the foot 59 is not case hardened. This results in the foot being minutely sticky and of a higher friction than the rest of the wiper element. This also assists in flipping of the wiper portion 46 at the commencement of the return stroke of the wiper element because the foot will tend to hold to the glass for a fraction of a second whilst the rest of the system commences its return. The foot 59 in effect becomes a pivot point and thereby enhances the ability of the element 40 to flip in the direction of the return stroke. Since modifications within the spirit and scope of the invention may readily be effected by persons skilled within the art, it is to be understood that this invention is not limited to the particular embodiment described by way of example hereinabove.

Claims: THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: 1. A windscreen wiper blade assembly clip for a windscreen wiper blade assembly having a blade frame including plural pairs of opposed claws, a backing strip having first and second channels for alternatively receiving a wipe blade element, the backing strip having a first pair of rails which include longitudinal edges spaced apart by a first predetermined distance and a second pair of rails having longitudinal edges spaced apart by a second predetermined distance which is greater than the first predetermined distance, the backing strip being coupleable to the blade frame by engaging either the first or second pair of rails with the opposed claws depending on the size of the opposed claws, and by the blade element being located in the first or second channels dependent upon which of the first or second pair of rails are engaged with the opposed claws, said windscreen wiper blade assembly clip including: a base section for location at an end of the backing strip; a first pair of legs coupled to and extending transverse to the base section and adapted to overlie the first pair of rails of the backing strip, the first pair of legs being spaced apart by a first predetermined distance; a second pair of legs coupled to and extending transverse to the base section and being opposed to the first pair of legs, the second pair of legs being adapted to overlie the second pair of rails, the second pair of legs being spaced apart a second predetermined distance which is greater than the first predetermined distance at which the first pair of legs are spaced; abutment members on each of the first and second pair of legs; attachment means for attaching the clip to the backing strip; and wherein dependent on which of the first or second rails are engaged with the opposed claws, the first or second pair of legs which overlie that pair of rails are, in use, engaged with one pair of the opposed claws by location of the abutment members behind said one pair of opposed claws to secure the backing strip to the one pair of opposed claws to limit longitudinal movement of the backing strip relative to the opposed claws. 2. The clip of claim 1 wherein, each abutment member is defined by a prong located at an end of each leg in the first and second pair of legs. 3. The clip of claim 1 wherein, the attachment means comprises a securing tab located between the first pair of legs or the second pair of legs, the securing tab, in use, being folded and puncturing the backing strip to secure the clip to the backing strip. 4. The clip of claim 1 wherein, the prongs have tapered side edges for camming engagement with the one pair of opposed claws so that the prongs can easily engage behind the one pair of opposed claws. 5. The clip of claim 1 wherein, the legs have cutout sections between the prongs and the base section and fingers arranged transverse to the legs, the fingers being, in use, arranged beside the first and second pair of rails so that the prongs limit movement of the backing strip in one longitudinal direction and the cutout section and fingers limit movement of the backing strip in the opposite longitudinal direction. 6. The clip of claim 1 wherein, the backing strip comprises a centre web, a first pair of arms extending perpendicular to the centre web in a first direction and a second pair of arms extending perpendicular to the centre web in a second direction opposite the first direction, the first pair of rails being arranged at ends of the first pair of arms and extending perpendicular to the first pair of arms and parallel to the centre web, the second pair of rails being arranged at ends of the second pair of arms and being perpendicular to the second pair of arms and parallel to the centre web. 7. The clip of claim 1 wherein, the first and second channels are defined between the first pair of arms and the centre web and between the second pair of arms and the centre web respectively. 8. The clip of claim 1 wherein, the first and second pair of rails have inwardly directed flanges which define restricted entrance slots into the first and second channels. . The clip of claim 1 wherein, the blade element has a base portion, a neck portion and a wiper portion, the base portion and the neck portion being a slidable fit into one of the channels and one of the restricted entrance slots and the wiper portion extending outwardly from the backing strip. 10. A backing strip for a windscreen wiper blade assembly, the windscreen wiper blade assembly having a blade frame including pairs of opposed claws, the backing strip including: first and second channels for alternatively receiving a wiper blade element, the backing strip having a first pair of rails which include longitudinal edges spaced apart by a first predetermined distance and a second pair of rails having longitudinal edges spaced apart by a second predetermined distance which is greater than the first predetermined distance, the backing strip being coupleable to the blade frame by engaging either the first or second pair of rails with the opposed claws dependent upon the size of the opposed claws, and by the blade element being located in the first or second channel dependent upon which of the first or second pair of rails are engaged with the opposed claws; a first clip arranged at one end of the backing strip and having a pair of legs which overlie the first pair of rails, the legs being spaced apart by a first predetermined distance; a second clip arranged at the other end of the backing strip and having a pair of legs which overlie the second pair of rails, the second pair of legs being spaced apart by a second predetermined distance which is greater than the first predetermined distance at which the first legs are spaced apart; abutment members on each of the first and second pair of legs of the first and second clips; and wherein dependent upon which of the first or second pair of rails are engaged with the opposed claws, the legs of the first or second clip which overlie that pair of rails are engageable with one of the opposed pair of claws so that the abutment members are arranged behind the said one of the pair of opposed claws to secure the backing strip to the one pair of opposed claws to limit longitudinal movement of the backing itrip relative to the opposed claws. 11. A backing strip for a windscreen wiper blade assembly which assembly includes plural pairs of opposed claws for engaging the backing strip and holding the backing strip in the blade assembly, said backing strip comprising: a first pair of rails having longitudinal side edges which are spaced apart by a first predetermined distance; a second pair of rails which have longitudinal edges spaced apart by a second predetermined distance; and a third pair of rails which have longitudinal side edges spaced apart by a third predetermined distance. 12. The backing strip of claim 1 wherein, the backing strip includes a centre web: a first pair of arms extending transverse to the centre web in a first direction; the first pair of rails being arranged on the first pair of arms; a second pair of arms extending transverse to the centre web in a direction opposite to the first pair of arms; the second pair of rails being arranged on the second pair of arms; and the third pair of rails being defined by an extension of the centre web. 13. A backing strip according to claim 11 wherein, the backing strip has a first channel for receiving a blade element which is defined between the first pair of arms and the centre web and a second channel for alternatively receiving the blade element depending upon which of the first or second pair of rails are engaged with the claw of the blade assembly, the second channel being defined between the second pair of arms and the centre web. 14. A backing strip according to claim 11 wherein, the first and second pair of rails include inwardly directed flanges which define a restricted entrance slot to the first and second channels. 15. A backing strip and clip combination for a windscreen wiper blade assembly which has opposed claws for receiving the backing strip, including: a backing strip having at least first and second pairs of rails for engaging the opposed claws of the windscreen wiper blade assembly; a clip arranged at one end of the backing strip and having; a) a base section for location at the end of the backing strip; b) a first pair of legs overlying the first pair of rails of the backing strip, a second pair of legs overlying the second pair of rails, and an attachment tongue for engaging the backing strip and securing the clip to the backing strip; and wherein the clip is held firmly to the backing strip by the base section which prevents substantial movement of the clip relative to the backing strip in a first direction parallel to the longitudinal direction of the backing strip, the attachment tongue which prevents substantial movement of the clip away from the backing strip in a direction opposite the first direction, the first pair of legs which prevent substantial movement of the clip in a third direction perpendicular to the longitudinal direction of the backing strip, and the second pair of legs which prevent substantial movement of the clip in a fourth direction perpendicular to the longitudinal axis of the backing strip and opposite to the third direction. 16. A backing strip and clip combination for a windscreen wiper blade assembly having a blade frame including plural pairs of opposed claws, the backing strip having first and second channels for alternatively receiving a wipe blade element, the backing strip having a first pair of rails which include longitudinal edges spaced apart by a first predetermined distance and a second pair of rails having longitudinal edges spaced apart by a second predetermined distance which is greater than the first predetermined distance, the backing strip being coupleable to the blade frame by engaging either the first or second pair of rails with the opposed claws depending on the size of the opposed claws, and by the blade element being located in the first or second channels dependent upon which of the first or second pair of rails are engaged with the opposed claws, said windscreen wiper blade assembly clip including: a first pair of legs overlying the first pair of rails of the backing strip, the first pair of legs being spaced apart by a first predetermined distance; a second pair of legs opposed to the first pair of legs, the second pair of legs overlying the second pair of rails, the second pair of legs being spaced apart a second predetermined distance which is greater than the first predetermined distance at which the first pair of legs are spaced; abutment members on each of the first and second pair of legs; attachment means for attaching the clip to the backing strip; and wherein dependent on which of the first or second rails are engaged with the opposed claws, the first or second pair of legs which overlie that pair of rails are, in use, engaged with one pair of the opposed claws by location of the abutment members behind said one pair of opposed claws to secure the backing strip to the one pair of opposed claws to limit longitudinal movement of the backing strip relative to the opposed claws. 17. The backing strip and clip combination of claim 16 wherein the clip is a single integral clip having a base section and the first and second pair of legs being connected to the base section and extending transverse with respect to the base section. 18. The backing strip and clip combination of claim 16 where the clip is formed in two separate clip halves, each half having a respective one of the first and second pair of legs.

Inventors: ABBOTT BARRY JAMES, ABBOTT VALERIE MARGARET, CLARKE STEPHEN JAMES, DONCHI DINO, ABBOTT, BARRY, JAMES, ABBOTT, VALERIE, MARGARET, CLARKE, STEPHEN, JAMES, DONCHI, DINO
Applicants: CLEAN SCREEN WIPERS PTY LTD, CLEAN SCREEN WIPERS PTY. LTD.
Application year: 1994
Main classification: B60S1
IPC codes: B60S1